This invention relates to an optical system for use with a source of corpuscular energy such as a laser. More particularly, this invention relates to an improved method and apparatus for aligning the mirrors of a laser optical system.
The usage of lasers in recent times has been extended to high power industrial applications. In these applications the lasers are used for cutting and welding of heavy workpieces by means of converging and focusing a high powered laser beam from a supply source onto the workpiece surface. The converging and focusing is accomplished by means of an optical system using mirrors. One such optical system is shown in U.S. Pat. No. 3,907,408 to Engel, assigned to the assignee hereof. With that reflective optical system, three mirrors are used to change the direction of a supply beam from a source of corpuscular energy such as a laser source. The beam is reflected off a 45.degree. angle planar mirrow within an optical system housing forwardly 90.degree. from the beam axis to impinge upon a concave mirror adjustably mounted in the forward end of the housing. From here, the beam is reflected back along the housing axis and converged to impinge upon a centrally disposed mirror, which is a convex mirror mounted within a bore in the 45.degree. mirror. The beam is then reflected forward through an aperture in the concave mirror and converged to a point of focus exterior to the mirror housing. With this system, all mirrors are adjustable for purposes of alignment.
This adjustability of all three mirrors is somewhat disadvantageous since it results in both a complexity of parts and therefore increased cost, and also complexity in alignment procedures.